Pod yield and phosphorus-use efficiency in groundnut (Arachis hypogaea) as influenced by citric acid and its delivery methods under a semi-arid agro-ecosystem

摘要

A field experiment was conducted during 2009-11 at Junagadh, Gujarat to find out the effect of citric acid (CA) and its delivery methods on yield, nutrient uptake and use efficiencies of phosphorus in groundnut {Arachis hypogaea L.). Results (mean ofthree years) revealed that application of citric acid at 2 kg along with farmyard manure (FYM) at 2 t/ha recorded significantly higher pod yield (2.61 t/ha), harvest index (36%) and net returns (?38,283/ha), which were 28.6, 22.0 and 44.5% higher respectively, over FYM at 2 t/ha without citric acid. Soil available P content (18 kg P/ha) significantly increased with citric acid at 6 kg along with single super phosphate (SSP) at 250 kg/ha over control. Citric acid at 4 and 6 kg along with SSP at 250 kg/hasignificantly increased P content in pod and haulm, respectively. P uptake significantly increased with citric acid at 4 kg/ha. Application of citric acid at 2 kg along with FYM 2 t/ha (17.2 kg P), citric acid at 4 kg along with SSP 250 kg/ha (17.2 kg P) and citric acid at 4 kg along with FYM 1 t/ha (8.6 kg P) recorded higher agronomic efficiency (19.5%), recovery efficiency (10.8%) and P harvest index (69%) respectively, over control plots. Application of higher levels of citric acid decreased yield,P uptake and P-use efficiencies. Thus, application of 2 kg citric acid along with FYM at 2 t/ha found appropriate in enhancing groundnut yield and net returns under semi-arid agro-ecosystem.